For example, Patent Document 1 discloses a battery pack that includes stacked battery boxes, which are battery modules each including a plurality of battery cells. A battery controller is arranged between stacked battery modules to control charging/discharging of the battery cells.
According to the above described configuration, a dead space exists between the stacked battery modules. If the dead space is increased, the dimension of the battery pack in the stacking direction of the battery modules is increased, accordingly. A greater size of the battery pack unfavorably increases the area occupied by the battery pack when mounted in a vehicle.